Dissecting Microscope Low objective 4 X Times 10

Dissecting Microscope Low objective 4 X Times 10 X (ocular lens) Total magnification 40 X

Cell Organelles

Cell Organelles Organelle= “little organ” Everything in a cell except the nucleus is cytoplasm

Cell Membrane Boundary of the cell Made of a phospholipid bilayer

Nucleus Control center of the cell Contains DNA Surrounded by a double membrane Usually the easiest organelle to see under a microscope Usually one per cell

Nucleus What does DNA stand for? Deoxyribonucleic Acid What is the packaged form of DNA called? Chromosomes

Cytoskeleton Acts as skeleton and muscle Provides shape and structure Helps move organelles around the cell Made of three types of filaments

Cytoskeleton (MF) Actin micro filaments (MT) Microtubules

Endoplasmic Reticulum A. k. a. “ER” Connected to nuclear membrane Highway of the cell Rough ER: studded with ribosomes; it makes proteins Smooth ER: no ribosomes; it makes lipids

Smooth Endoplasmic Reticulum also regulates and releases calcium ions and processes toxins Smooth ER: no ribosomes; it makes lipids

Smooth and Rough Endoplasmic Reticulum

Ribosome Site of protein synthesis Found attached to rough ER or floating free in cytosol Produced in a part of the nucleus called the nucleolus

Golgi Apparatus Looks like a stack of plates Stores, modifies and packages proteins Molecules transported to and from the Golgi by means of vesicles

Golgi Apparatus

Lysosomes Garbage disposal of the cell Contain digestive enzymes that break down wastes

Lysosomes

Mitochondria “Powerhouse of the cell” Cellular respiration occurs here to release energy for the cell to use Bound by a double membrane Has its own strand of DNA

Mitochondria

Centriole Aids in cell division Usually found only in animal cells Made of microtubules

Centriole

Quick Review Which organelle is the control center of the cell? Nucleus Which organelle holds the cell together? Cell membrane Which organelle has digestive enzymes that help break down waste? Lysosome What does E. R. stand for? Endoplasmic reticulum